The present invention relates to a method for treating RNA viral infections by utilizing the type of specified RNA chain terminating agents disclosed herein. The class of compounds useful in treating those viral infections are 3'-substituted ribonucleosides. In contrast to the extensive literature treatment wherein the effects of 2'-deoxy, 3'-substituted nucleosides were studied, the agents disclosed herein useful in the method of the present invention relate to agents acting as RNA chain terminators, particularly as potent inhibitors of RNA virus replication. Although not wanting to be limited by theory, it is believed that these compounds interfere with messenger RNA synthesis and also block viral genome replication.
In the past, numerous alpha and beta-D-ribofuranosyl nucleosides had been used to study antiviral activity against Herpes simplex virus-1, Herpes simplex virus-2, Vaccinia virus, Vesicular stomatitius virus, Poliovirus-1, Coxsackie virus B4, Parainfluenza virus-3, Reovirus, Sindbis virus, Semliki forest virus, Rhinovirus 1A, Rhinovirus-9. Of the various compounds studied in relation to these viruses, three compounds in particular showed marked biological activity. However, the compounds of the present invention have not been studied specifically for RNA viral activity.
More recently, 3'-O-methyl nucleosides have been shown to inhibit Vaccinia virus RNA synthesis in infected cells and 3'-fluoroguanosine has been shown to be an antiviral agent. The viruses reviewed with the fluoroguanosine are Reovirus 1, Sindbis virus, Coxsackie virus and Semliki forest virus.
An object of the present invention relates to providing a mechanism by which to correlate in vitro RNA chain terminator studies with in vivo such studies leading to the use of RNA chain terminators in controlling and/or treating RNA viral infections. Further, it is an object of the present invention to provide a method for treating RNA viral infections. These and/or other objects of the invention will become clearer with the more detailed description of the invention provided hereinbelow.